Hi, Am Mon, den 05.07.2004 um 14:38 Uhr -0400 schrieb John Russell: > I have read a few threads on this mailing list where file IO was > discussed. Specifically this thread > > http://www.daa.com.au/pipermail/pygtk/2003-November/006233.html > > which talks about running something like > > while 1: > data_o = child_o.readline() > textbuffer.insert(textbuffer.get_end_iter(), data_o) > textview.scroll_to_mark(textbuffer.get_insert(), 0) > while gtk.events_pending(): > gtk.mainiteration(gtk.FALSE) > > to read a line, update the UI and read some more. > > However, I am reading from the stdout of a file descriptor returned > from popen and the process that I am running sometimes thinks for a > while. So if its thinking and doesn't output anything, the UI will > freeze while it blocks on the readline() call. When a line shows up, > it is appended, the UI updates all of a sudden, and then back to > blocking where the UI doesn't update.
Switch the stuff to non blocking mode :) > How can I make this more smooth? I was thinking of threads, but I > couldn't figure out how to stop the process if, for example, the user > hit cancel or something. I tried join(0) but the process just sat > there, even after my program had exited. I had to kill -9 the spawned > process. I'm sure there is a way to do this as I see it all the time. > e.g. the output of cdrecord in xcdroast... that kind of thing. How > is this done? I use non-blocking reads, no threads, but if you want, have a look at http://cvs.sourceforge.net/viewcvs.py/*checkout*/traveller/traveller/spawner.py?rev=1.9 That's how I did it... As that is under LGPL, you can just use that (spawn() returns the pid, the object has a onGetData event you connect to using spawner.onGetData.append((self, getdata_cb)) and will get the pid and group and data) or you can write your own :) The important points are: open stuff with Popen2.Popen4, manipulate the returned "fromchild" by fcntl to set flag O_NONBLOCK, use gtk.input_add to make it callback on read and except. In that callback do the gui update. If read() function throws exception, it means nothing bad; if read() function returns "" that means "End of file", and that means, the command (the pipe endpoint) has been terminated. Hope that helps. cheers, Danny
signature.asc
Description: Dies ist ein digital signierter Nachrichtenteil
_______________________________________________ pygtk mailing list [EMAIL PROTECTED] http://www.daa.com.au/mailman/listinfo/pygtk Read the PyGTK FAQ: http://www.async.com.br/faq/pygtk/
